1. Technical Field
This invention generally relates to router bits. More particularly, the invention relates to a router bit having a mechanism for setting the position of the cutter blades relative to the upper surface of a chuck in a rotary tool. Specifically, the invention relates to a router bit having a body and shank, where the shank includes a collar adapted to rest on the upper surface of the chuck and to thereby maintain the cutter blades of the router bit at a set distance from the upper surface of the chuck.
2. Background Information
Routers are used for a variety of woodworking purposes including cutting of complimentarily shaped profiles such as tongue and groove joints, finger joints and the shaped edges of a table and leaf for a drop-leaf table. In order to cut such complimentarily shaped profiles, a first router bit is attached to the router by inserting the shank of the bit into the bore of a chuck on the router. The shank is locked into place by tightening the collet in the chuck and the tool is then brought into contact with a first workpiece, such as a piece of wood or plastic. The first router bit is then rotated by the router motor so that a first profile is cut into the first workpiece. The operator then removes the first router bit and a second router bit is inserted and secured to the router. The second router bit is of a different cutting configuration to the first router bit. The second router bit is rotated and brought into contact with a second workpiece. The second router bit cuts a second profile into the workpiece. The first and second profiles are complimentarily shaped and are adapted to enable the first and second workpieces to be brought into in interlocking engagement.
One of the most common problems experienced by carpenters or other users when performing this task is that the first and second router bits must be inserted into the collet to exactly the same degree so that the depth of the cuts in the two workpieces matches exactly. If this is not achieved, then when the two profiles are brought together to interlock with each other, one workpiece will tend to be slightly vertically displaced relative to the other. This causes the interlock of the two workpieces to be either aesthetically displeasing or nonfunctional.
A second problem experienced by carpenters or users when using presently known router bits is that the bits tend to vibrate quite a lot and this makes precision work with the router or rotary tool more difficult. Additionally, the router bit may be prone to premature failure because of the combination of vibration in the router bit and the force exerted on the bit by the user during cutting.
There is therefore a need in the art for a mechanism for ensuring that a router bit may be inserted into the collet of a router at a predictable depth. There is furthermore a need in the art for a mechanism for ensuring that complimentarily shaped router bits may be inserted into a router at a predictable and substantially constant depth. There is also a need in the art for a router bit that vibrates less during cutting and that is less prone to premature failure.